Have the basic one, paid £25 for it last September on my cob, and it hasn't leaked... Put it this way, my reproofed and repaired last year Masta LW has more holes and leaks more than the Tesco one! However I wouldn't say it is the most breathable of things to a certain degree!
I was really suprised how good they are! I have the cheap mw turnout which seems really waterproof, its cotton lined though. I got the more expensive 300gm one too (deluxe arctic maybe?) and its really good - fits well, the hood doesn't blow up in the wind, and its nylon lined.
I bought the lightweight one which saw Clyde through last autumn-very good. However, being a bit of an eejit, I washed it and put it away without further thought. I put it on the poor boy when the rain started and was horrified to find him soaking wet next day. Got sent to Milletts by OH with a huge flea in my ear for proofing stuff. Having re-proofed the rug, it now stays dry. Very pleased with it,actually. You can't blame the rug for being owned by a twit.